Robert Edwin Hastewell was born in Haltwhistle, Northumberland, England on 11 February 1881 and was articled to Henry Higginson (1862-1922) in Carlisle from 1899 to 1903. He also studied at Carlisle School of Art in 1903-04. He then worked as an assistant to Thomas Geoffry Lucas (1872-1947) in 1904-05, during which time he attended King's College, London.
Hastewell commenced independent practice in Carlisle in 1905 and was in partnership with Higginson in 1905-06. He was later in partnership with John Alfred Smith as Hastewell & Smith in Colwyn Bay, Denbigh. The partnership was dissolved in 1938. He was also in partnership with John Hampson as Hastewell and Hampson in Colwyn Bay, Denbigh. This partnership was dissolved in 1939
Hastewell passed his qualifying exam in 1909 and was elected an Associate of the Royal Institute of British Architects (ARIBA) the following year.
His address was given as The Grange, Haltwhistle, Northumberland in 1910; West Gate Chambers, Haltwhistle, Northumberland in 1910 and 1914; Rhos Road, Rhos-on-Sea, Colwyn Bay, Denbigh in 1918 and 1920; and "The Hill", Scotby, Carlisle in 1939. He died in Border, Cumberland on 6 November 1962
Directory of British Architects 1834-1914. Compiled by Antonia Brodie, et al. Volume 1: A-K London; New York: British Architectural Library, Royal Institute of British Architects/Continuum, 2001